Millimeter-wave bands are of increasing interest for the satellite industry and under discussion aspotential 5G bands. Antennas for 5G applications make use of the shorter element sizes at these highfrequencies to incorporate a larger count of radiating elements. These antenna arrays are essential forbeamforming operations that play an important part in next generation networks.This white paper introduces some of the fundamental theory behind beamforming antennas. In addition tothese basic concepts, calculation methods for radiation patterns and a number of simulations results, aswell as some real world measurement results for small linear arrays are shown. Due to the bandwidthslikely to be employed in such applications, a non-standard way of graphical representation is proposed.